Method of glazing hollow clay bodies



1940 R. A. SI-IIPLEY 2,212,622

METHOD 0F v GLAZING HOLLOW CLAY BODIES Filed Aug. 18, 1938 p INVENTOR.

ATTORNEY.

Patented Aug. 27, 1940 UNITED STATES PATENT OFFECE National Fireproofing Corporation, Pittsburgh, Pa., a, corporation of Pennsylvania Application August 18, 1938, Serial No. 225,516

1 Claim.

This invention relates to new and useful improvements in glazed conduits or hollow clay shapes produced by extrusion process, and it is among the objects thereof to provide a method of spraying a fluid coating on the interior of a single or multiple cell hollow clay shape, while being extruded, to thereby avoid extra handling of the product for spraying after it has been removed from the extruding device.

In the accompanying, drawing constituting a part hereof, and in which like reference characters designate like parts:

Fig. 1 is a view partially in side elevation and partially in section of an extruding head and spray for making hollow clay articles;

Fig. 2 a top plan view thereof; and

Fig. 3 is a View similar to Fig. 1 taken at right angles to the view of Fig. 1. p H

In the drawing, the numeral I designates a die plate, 2 the core and 3 the face plate of a hollow clay ware die, the die being bolted to a machine barrel 4, as shown. A bridge 5 as shown in dotted lines of Fig. 2 extends across the rear of the die plate to support the core 2 and the spray nozzle generally designated by the numeral 6. The reference numeral l designates a hollow clay column which is being extruded from the die, the purpose of the invention being to provide means whereby the fluid coating is applied on the inner wall of the column '5 by means of a spray 3 emitted from the nozzle 8, as shown in Fig. 3 of the drawing. The core 2 is hollow and is provided with a threaded nipple 9 to which the spray nozzle 6 is secured.

A tube l9 extends through the hollow core 2 and opens into a chamber ii that communicates through passages l2 and i3 with a threaded opening M in the die plate at which point a conduit leading to a source of glaze or slip is attached. The passages l2 and it are drilled and passage i2 is plugged at H5. The glaze flowing through the passages 52 and I3 enters the chamber II and passes outward through the interior of the hollow tube Hi. Air is supplied to the space surrounding the tube In, through passages it and [1, the latter being plugged at 18, and a source of compressed. air is conducted through passages it and ii to the hollow interior of the core 2, from which it passes into the nozzle 6. The construction of the spray nozzle 5 is no part of the present invention, and it suflices to describe it as functioning to spray the glaze or slip on the 5 inner wall of the extruded clay column i, which is in the shape inore clearly shown in the crosssectional view of Fig. 2.

In the operation of the device, the clay passes outwardly, as viewed in Fig. 1, from the machine 10 auger, around the bridge 5 and into the mouth of the die, which is the flared portion constituted by the space between the tapered portion of the core 2 and the tapered portion of the die plate l. The clay is then shaped by its furtherpas- 16 sage through the die to the desired form, as exemplified in Fig. 2 of the drawing. While being thus extruded, the spray 8 is continuously applied to the inner surface of the hollow clay cell or ware to coat it with the glaze or slip, which upon 20 the subsequent firing oi the clay wall produces a glazed coat on the inner surface thereof.

By this method of applying the spray while the clay body is extruded from the die, the extra spraying ope-ration heretofore employed is eliminated. This method also eliminates handling and breakage and results in a substantial saving, with a resultant reduction in cost of the production.

Although one embodiment of the invention has been herein illustrated and described, it will be evident to those skilled in the art that it may be applied for the spraying of multiple cell articles by providing a spray in each cell, or otherwise modified in the details of construction, without departing from the principles herein set forth.

I claim:

The method of applying a surface coating ma terial to the inner surface of hollow extruded clay articles which comprises continuously extruding the clay in the form of a hollow column through a shaping die and spraying a liquid coating material simultaneously against the entire inner wall of the extruded clay article as it emerges from the die and before it is severed.

ROY A. SHIPLEY. 

